Wyniki wyszukiwania - BazTech

1

Efficient and conservative estimation reliability analysis of strip footing on spatially variable c - ϕ soil using random finite element limit analysis

Szabowicz Hubert, Kawa Marek, Puła Wojciech

Studia Geotechnica et Mechanica

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2025

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Vol. 47, nr 1

17--35

EN

he study deals with reliability analysis of strip foundation on spatially variable c - ϕ soil. The spatial variability of soil strength parameters, namely cohesion c and friction angle ϕ is modelled using anisotropic uncorrelated random fields, generated with the Fourier series method. Random finite element limit analysis (RFELA) providing a rigorous lower and upper bound for bearing capacity for individual Monte-Carlo simulations is employed. Additional use of adaptive meshing refinement algorithm leads to a significant reduction of the relative difference between statistical moments of obtained lower and upper bound results. The influence of the horizontal and vertical scales of fluctuation and foundation depths on the mean and standard deviation of the obtained bound moments is investigated. Additionally, the rigorousness of the mean and standard deviation of both considered bounds estimation is checked. As a result of the analysis, a novel approach based on a mixed distribution that combines lower and upper bound moments is introduced. As shown, this approach offers significant benefits by providing conservative and relatively precise measures of reliability which can be obtained in reasonable computation time. The proposed method seems to be adequate for practical engineering reliability analysis of foundation bearing capacity and other limits states problems.

2

Failure identification and isolation of DC-DC boost converter using a sliding mode controller and adaptive threshold

Khater Fatma, Aibeche Abderrezak, Fellag Sid Ali, Doghmane Mohamed Zinelabidine, Akroum Hamza

Diagnostyka

|

2024

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Vol. 25, No. 3

art. no. 2024303

EN

DC-DC converters have become essential components in various industrial applications, including aerospace, electric vehicles, and renewable energy systems. However, ensuring enhanced reliability remains a critical challenge for these converters. Fault diagnosis and reliability analysis are crucial for preventing damage and minimizing maintenance costs. This study focuses on investigating the operational behavior of DC-DC boost converters under normal and faulty conditions, precisely targeting open-circuit and short-circuit faults in converter switches. To achieve this, an adaptive threshold approach is introduced for effective fault detection. The adaptive threshold value is calculated based on measured voltage and current signals, along with their corresponding reference signals from the primary control system. The research is structured into two parts: the first part addresses sliding mode control aspects, ensuring regulated output voltages, output currents, and capacitor voltage for sustained converter operation. The second part investigates fault diagnosis, analyzing the impact of defective DC-DC converters on the overall electrical system functionality. The proposed algorithm's performance is evaluated and validated through simulations in MATLAB/Simulink environment. Furthermore, based on the results’ comparison, the proposed approach of the sliding mode controller and adaptive threshold contributes to enhancing the reliability of DC-DC converters and enables effective fault detection and isolation.

3

Two-dimensional modeling of car reliability during warranty period

Sliż Piotr, Wycinka Ewa, Jackowska Beata

Zeszyty Naukowe. Transport / Politechnika Śląska

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2023

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z. 121

223--239

EN

The paper focuses on presenting the concept of two-dimensional modeling of passenger car reliability during the warranty period. The main objective of this paper is to detect the regularity in the intensity of the number of first failure reports during the warranty period. The two-dimensional distribution of the time and mileage of failure-free exploitation is estimated. The period from the date of purchase to the first warranty repair is analysed. The concept presented incorporates the existing state of knowledge on two-dimensional warranties, expanding it through the use of a nonparametric approach and probability smoothing with the use of P-splines. The estimation involved censored data, i.e., data on vehicles that were not submitted for warranty repair within the warranty limits of time and mileage. The originality of this paper entails the combination of a nonparametric approach with probability smoothing. The statistical analyses presented in the paper were carried out on a population of 1005 vehicles of two car brands sold and serviced in 2011-2021 at the Authorized Service Station (Dealership). There were sales, repair, and warranty claim databases.

4

Water absorption, impact resistance and strength reliability of concrete incorporating sintered fly ash aggregate under drop weight impact load

Baskaran Ranjith Babu, Nagarajan M.

Engineering Transactions

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2023

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Vol. 71, iss. 2

197--211

EN

ASTM and ACI methods were used to determine the water absorption and impact resistance of M30 grade concrete containing different percentages of sintered fly ash aggregate (SFA) ranging from 20%, 40%, 60%, 80%, and 100%. In the concrete laboratory, the parameters of the concrete mix, including fresh density, slump value, dry density, compressive strength, and impact resistance, were determined. The fresh and dry densities of concrete mix decrease as the quantity of SFA used as substitute increases. The 100% substitution of SFA in concrete results in a slump value of 200 mm, a fresh density of 1946 kg/m3 , a dry density of 1911 kg/m3 , and water absorption of 3.5%, with a compressive strength of 12.3 MPa. For the drop weight impact resistance test, reliability analysis was conducted to determine the level of reliability of each concrete mix for varying SFA. Using reliability analysis, the failure analysis owing to impact load determined the energy absorption of the concrete mix.

5

Przemysłowe akceleratory elektronów i ich zastosowania w technologiach radiacyjnych : aspekty niezawodnościowe i ekonomiczne

Bułka Sylwester, Zimek Zbigniew

Elektronika : konstrukcje, technologie, zastosowania

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2023

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Vol. 64, Nr 1

25--28

PL

Niezawodność czyli prawdopodobieństwo, że akcelerator może pełnić swoje funkcje w określonym czasie w wyznaczonych warunkach, oraz dostępność czyli czas, w którym akcelerator wypełnia swoje zadania to parametry, które w zastosowaniach przemysłowych nabierają podstawowego znaczenia. Wyroby modyfikowane radiacyjnie muszą spełniać wszystkie kryteria przydatności zgodnie z oczekiwaniami rynku, a jednocześnie technologie radiacyjne muszą wykazać się lepszymi wskaźnikami techniczno-ekonomicznymi w porównaniu do konwencjonalnych technologii aktualnie istniejących. Stąd konieczność optymalizacji decyzji inwestycyjnych głównie z uwagi na wysokość kosztów związanych z zakupem akceleratora i jego eksploatacją. Konieczne jest prowadzenie nieustannych wysiłków dla zwiększenia zrozumienia przydatności technologii radiacyjnych, co może być ważnym czynnikiem wzrostu tego przemysłu. W obecnych warunkach współpraca z przemysłem staje się niezbędnym warunkiem inicjowania i rozwijania badań aplikacyjnych niezbędnych przy opracowaniu nowych technologii radiacyjnych.

EN

Reliability that is the probability, that the accelerator can function in the definite time in appointed conditions. Accessibility is the time, in which the accelerator functions properly. Both parameters arę becoming important for industrial facilities exploitation. Products modified by radiation have to fulfill all criteria of usefulness according to market expectations. Radiation technologies have to simultaneously be characterized by better technical and economic ratings in comparison with conventional technologies. Hence the necessity of the optimization of investment decisions related to costs connected with the accelerator purchase and exploitation. The efforts arę necessary for enlargement of the understanding of the radiation processing usefulness what can be the important factor of this industry growth in future. The co-operation with the industry becomes the indispensable condition of initiating and unrolling applied study related to new radiation technologies development.

6

Reliability analysis method of coupling optimal importance sampling density and multi-fidelity Kriging model

Xie Jiayu, Tian Zongrui, Zhi Pengpeng, Zhao Yadong

Eksploatacja i Niezawodność

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2023

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Vol. 25, no. 2

art. no. 161893

EN

The commonly used reliability analysis approaches for Kriging-based models are usually conducted based on high-fidelity Kriging models. However, high-fidelity surrogate models are commonly costly. Therefore, in order to balance the calculation expense and calculation time of the surrogate model, this paper proposes a multi-fidelity Kriging model reliability analysis approach with coupled optimal important sampling density (OISD+MFK). First, the MEI learning function is proposed considering the training sample distance, model computation cost, expected improvement function, and model relevance. Second, a dynamic stopping condition is proposed that takes into account the failure probability estimation error. Finally, the optimal importance sampling density is incorporated into the reliability analysis process, which can effectively reduce failure probability estimation error. The results of the study show that the approach proposed in this paper can reduce the calculation cost while outputting relatively accurate failure probability evaluation results.

7

Process machining allowance for reliability analysis of mechanical parts based on hidden quality loss

Wang Jingang, Liu Xintian, Wang Xu, Jin Kai

Eksploatacja i Niezawodność

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2023

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Vol. 25, no. 4

art. no. 171594

EN

The machining allowance variation is significant for the reliability of a part during the machining process. Usually, when the machining allowance of a part increases, the machining and production cost also increase. When the machining allowance decreases, the machining surface will have defects. The parts will produce manyscraps andreliability will decrease. The machining allowance of a part consists of multiple process machining allowances. To analyze the impact caused by machining allowance variation, the hidden quality loss and process machining allowance are combined through theprocess capability index (PCI). Then the asymmetric quadratic quality loss function (AQF) and quadratic exponential function (QEF) are used to analyze them. A prediction model of hidden quality loss of process machining allowance is proposed. On the premise that the quality characteristic value obeys normal function distribution, a numerical model is given and used to obtain process machining allowance-inherent reliability of the product. The actual case is used to compare and verify the two models.

8

Mean residual lifetime assessment approach for a multi-state standby system

Karadayi Ebru, Funda Iscioglu

Eksploatacja i Niezawodność

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2023

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Vol. 25, no. 2

art. no. 166328

EN

In this paper, a new MRL assessment approach for a multi-state standby system is considered. The three-state system is backed up with a binary cold standby unit. Given that the system is at a specific state at time t, obtaining the MRL is worth considering in conducting the maintenance and repair plans of the system. For different degradation rates and time points, MRL results are examined. An HCTMP is considered for the degradation. Therefore, when the system is observed to be at its perfect state, the MRL decrease with an increase in all the failure rates of the system. However, when the system is observed to be at its partial state, the MRL is not affected by the increase in the failure rate pertained to the perfect state. The MRL when the system has known to be failed before time t and backed up with the standby unit increases with the time increase whereas the MRL when the system is at its perfect(or partial) state is constant when time increases. Moreover, cost evaluation of the system is analyzed. The results are supported with numerical examples and graphical representations.

9

Influence of impact load form on dynamic response of chock-shield support

Meng Zhaosheng, Ma Chen, Xie Yunyue

Eksploatacja i Niezawodność

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2023

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Vol. 25, no. 3

art. no. 168316

EN

Chock-shield support is usually used in undergroud coal mining to protect the roof. However, as the mining depth gets deeper, impact load that came from the roof becomes stronger and more frequent. This causes the support to bear a large number of dynamic loads, and reducing its reliability. To improve the support performance of the chock-shield support, the mixed-kinetic model was established using the mechanical-hydraulic co-simulation method. The load distribution law of the support joint under impact load form different stability forces, impact load amplitude, and impact frequency is discussed. The mechanical-hydraulic cooperative response of the chock-shield support are obtained. The results show that different joints show typical non-uniformity characteristic during the loading process. The proposed mechanical-hydraulic co-simulation method can more accurately obtain the dangerous points of hydraulic support reliability. The results of this study will help to improve the reliability of the chock-shield support.

10

An assessment of the reliability of CFRP composites used in nodes of friction after impact of UV-A impacts and thermal shocks

Krzyzak Aneta, Racinowski Damian, Szczepaniak Robert, Kosicka Ewelina

Eksploatacja i Niezawodność

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2023

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Vol. 25, no. 4

art. no. 174221

EN

This article describes the results of tribological research into epoxy-based composites reinforced with carbon fiber. The composites were subjected to accelerated tests simulating asemi-annual influence of environmental conditions of an elevated temperature, precipitation in combination with an influence of UV-A radiation of 0.83 W/m2 as well as cyclic thermal shocks causing a leap temperature difference of 116.5°C. The process of friction was conducted in conditions of dry friction and wet friction in the presence of water. The authors found apositive influence of a two-month impact of environmental conditions upon increasing wear resistance. They found a reduction in weight in conditions of friction with water. At the same time, a reliability analysis for the same boundary conditions showed an increased risk of critical composite damage. The article indicates areas of safe exploitation of composites and areas of the necessity of withdrawing composites from further exploitation under the assumed environmental and tribological loads.

11

Reliability estimation of underground horizontal fuel tank limit states

Sorn Przemysław, Sondej Mateusz, Górski Jarosław

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 2

art. no. e144588

EN

Fuel tanks are designed with regard to standard loads and operating conditions. The investigations of the paper show the impact of such factors as tank corrosion and other means on variation of stress fields and deformation of the underground horizontal tank shell. Introduction of probabilistic methods allows for structural reliability assessment. While the computational time of the entire tank FEM model is high the preliminary analysis is restricted to structural part only. The analysis makes it possible to optimize the structure with regard to construction costs.

12

Implicit neural state functions in hybrid reliability analysis of plane frame

Potrzeszcz-Sut Beata, Dudzik Agnieszka, Radoń Urszula

Archives of Civil Engineering

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2023

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Vol. 69, nr 4

55--71

EN

The objective of the article involves presenting innovative approach to the assessment of structural reliability analysis. The primary research method was the First Order Reliability Method (FORM). The Hasofer-Lind reliability index in conjunction with transformation method in the FORM was adopted as the reliability measure. The implicit limit state functions were used in the analysis. The formulation of the random variables functions were created in the Matlab software by means of neural networks (NNs). The reliability analysis was conducted in Comrel module of Strurel computing environment. In the proposed approach, Hybrid FORM method (HF) used the concept in which NNs replaced the polynomial limit state functions obtained from FEM (Finite Elements Method) for chosen limit parameters of structure work. The module Comrel referenced Matlab files containing limit state functions. In the reliability analysis of structure, uncertain and uncorrelated parameters, such us base wind speed, characteristic snow load, elasticity modulus for steel and yield point steel are represented by random variables. The criterion of structural failure was expressed by four limit state functions - two related to the ultimate limit state and two related to the serviceability limit state. Using module Comrel values of the reliability index with the FORM method were determined. Additionally, the sensitivity of the reliability index to random variables and graph of partial safety factors were described. Replacing the FEM program by NNs significantly reduces the time needed to solve the task. Moreover, it enables the parallel formulation of many limit functions without extending the computation time.

PL

Obecnie ocena niezawodności konstrukcji bazuje na wyidealizowanej koncepcji stanów granicznych i ich weryfikacji poprzez zastosowanie częściowych współczynników bezpieczeństwa. Rolą częściowych współczynników bezpieczeństwa jest zapewnienie wymaganego poziomu niezawodności konstrukcji. Metody probabilistyczne są naturalnym rozszerzeniem metody stanów granicznych. W praktycznych zastosowaniach istniejące oprogramowanie MES (Metoda Elementów Skończonych) jest często łączone z modułami do analizy niezawodności. Wadą takiego podejścia jest jednak długi czas obliczeń wynikający z wielokrotnych wywołań funkcji stanu granicznego dla różnych realizacji wektora zmiennych losowych. W artykule autorzy proponują alternatywne rozwiązanie problemu poprzez implementację hybrydowej metody FORM. Ocenę prawdopodobieństwa awarii, a tym samym obliczenie wskaźnika niezawodności Hasofera-Linda, uzyskujemy poprzez zastosowanie metody aproksymacyjnej FORM. W analizie wykorzystano niejawne funkcje stanów granicznych. Formułowanie funkcji granicznych dla pewnego zakresu zmiennych losowych zostało utworzone w programie Matlab za pomocą sieci neuronowych (SN). Analiza niezawodności została przeprowadzona w module Comrel środowiska obliczeniowego Strurel. Pakiet ten zawiera wbudowane interfejsy do definiowania funkcji stanów granicznych umożliwiając odwołanie do plików Matlaba zawierających zdefiniowane przez użytkownika funkcje stanu. Proponowana przez autorów hybrydowa metoda FORM łączy trzy algorytmy obliczeniowe - metodę elementów skończonych, sieci neuronowe oraz metodę aproksymacyjną probabilistycznej oceny niezawodności konstrukcji - FORM. Struktura algorytmu systemu jest więc mieszana, tzn. szeregowo-równoległa. Analiza zadania przebiega w czterech etapach.

13

Comprehensive importance analysis for repairable system components based on the GO method

Jiang Xiuhong, Wang Yuying, Li Jiaxin, Ye Linlin

Eksploatacja i Niezawodność

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2022

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Vol. 24, no. 4

785--794

EN

In order to effectively improve the reliability level of the permanent magnet synchronous motor (PMSM) drive system of electric aircraft, a component importance analysis based on the GO method for the repairable systems is proposed. Firstly, the system reliability model GO diagram is established according to the hardware schematic diagram of the PMSM drive system. Secondly, the steady-state availability and failure importance of the components are calculated. In addition, the criteria importance through intercriteria correlation (CRITIC) is adopted to determine the objective weights of steady-state availability and failure importance. The combined weighting is employed to obtain the importance of key components. Meanwhile, a system redundancy design based on the importance of components is proposed to provide data support for the design of the system. Finally, the feasibility and effectiveness of the proposed method are evaluated by an example of an electric aircraft PMSM drive system. This method provides a supporting basis for the optimization design of the entire system.

14

An adaptive PC-Kriging method for time-variant structural reliability analysis

Nan Hang, Li Hongshuang, Song Zhuocheng

Eksploatacja i Niezawodność

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2022

|

Vol. 24, no. 3

532--543

EN

The practical application of time-variant reliability analysis is limited by its computationally expensive models which describe the structural system behavior. This paper presents a new adaptive PC-Kriging (APCK) approach to accurately and efficiently assess the time-variant reliabilities. Time interval is firstly discretized with a series of time instants and then the stochastic process is reconstructed by standard normal random variables and deterministic function of time. PC-Kriging (PCK) models are built at each time instant to predict the instantaneous responses of performance function. To improve the accuracy and efficiency, a new update strategy based on the integration of U- and H- learning functions is developed to refine the PCK models of instantaneous responses. One or two best samples are identified by the proposed learning criterion for updating the PCK models. Finally, Monte Carlo simulation (MCS) is used to estimate the time-variant reliability based on the updated PCK models. Four examples are used to validate the accuracy and efficiency of the proposed method.

15

Automated Production Line Reliability Analysis of the Crankshaft Manufacturing Process

Enzi Abass, Khan Sardar Asif

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no. 1

15--27

EN

The producer focuses on producing parts that match the customer’s requirements during manufacturing the automotive engine parts. One of the essential automotive engine parts is a crankshaft used to translate movement from the pistons to the car axle. The crankshaft is a complex shape and difficult to produce accurate dimensions during the machining processes. Many machines are used to create the crankshaft. Therefore, many defects happen during the machining process, reducing reliability and increasing the manufacturing process’s production cost. This paper focuses on analyzing failure data and reliability of the crankshaft production line that occurs during the manufacturing process of one year. The common failure associated with the manufacturing process were ring screw, unbalanced crankshaft, broken drill screw, hub machining error, mains part machining error, and setup error. The paper aimed to determine and analyze the best failure fit between the distribution methods, such as Weibull, normal, lognormal, and exponential. Also, the reliability, hazard rate, surviving quantity, and failure density were calculated to evaluate the current situation and predict the reliability of the production line. Results proved the skewness of the data was positive equal to 3.33; the last months had the highest production failure rate, which is 53.8%, the normal method had a proper distribution of data depending on the Anderson-Darling (adj) values which is 1.367 when it compared with other methods, the normal method had the best fitting result depended on failure percentage, from 1% to 95% of the crankshafts production are expected to fail between 47.2676 and 1149.85 months respectively. The reliability of the production line decreased with manufacturing time increased. To reduce the failure and increase reliability, the maintenance system must be supported, analyze the sources that cause failure and downtime of the production line, continue the employee training system on an ongoing basis, and support the production line with modern technology. All analytical results and suggestions could be valuable to the production line to improve reliability and reduce the manufacturing process’s failure.

16

Computer analysis of dynamic reliability of some concrete beam structure exhibiting random damping

Bredow R., Kamiński M.

International Journal of Applied Mechanics and Engineering

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2021

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Vol. 26, no. 1

45--64

EN

An efficiency of the generalized tenth order stochastic perturbation technique in determination of the basic probabilistic characteristics of up to the fourth order of dynamic response of Euler-Bernoulli beams with Gaussian uncertain damping is verified in this work. This is done on civil engineering application of a two-bay reinforced concrete beam using the Stochastic Finite Element Method implementation and its contrast with traditional Monte-Carlo simulation based Finite Element Method study and also with the semi-analytical probabilistic approach. The special purpose numerical implementation of the entire Stochastic perturbation-based Finite Element Method has been entirely programmed in computer algebra system MAPLE 2019 using Runge-Kutta-Fehlberg method. Further usage of the proposed technique to analyze stochastic reliability of the given structure subjected to dynamic oscillatory excitation is also included and discussed here because of a complete lack of the additional detailed demands in the current European designing codes.

17

Failure-based sealing reliability analysis considering dynamic interval and hybrid uncertainties

Sun Bo, Yang Xi, Ren Yi, Wang Zili, Antosz Katarzyna, Loska Andrzej, Jasiulewicz-Kaczmarek Małgorzata

Eksploatacja i Niezawodność

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2021

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Vol. 23, no. 2

278--284

EN

In the reliability analysis of a sealing structure, radial clearance of the contact surface is usually regarded as a failure criterion, and the sample size is usually quite small, which brings great challenges to uncertainty quantification. Therefore, this paper proposes a reliability analysis method based on the leakage mechanism of the sealing. With the application of dynamic interval, the proposed method can be used to deal with problem of degradation in small sample to evaluate reliability. Moreover, the dynamic reliability with the mixture of the probabilistic and non-probabilistic variables can be obtained using the proposed method. An illustrative numerical case study of a spool valve is conducted in order to validate the proposed method and the implemented reliability sensitivity analysis. The proposed method is of great help in evaluating and predicting reliability with small degradation sample and hybrid uncertainties.

18

Health-aware and fault-tolerant control of an octorotor UAV system based on actuator reliability

Salazar Jean Carlo, Sanjuan Adrián, Nejjari Fatiha, Sarrate Ramon

International Journal of Applied Mathematics and Computer Science

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2020

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Vol. 30, no. 1

47--59

EN

A major goal in modern flight control systems is the need for improving reliability. This work presents a health-aware and fault-tolerant control approach for an octorotor UAV that allows distributing the control effort among the available actuators based on their health information. However, it is worth mentioning that, in the case of actuator fault occurrence, a reliability improvement can come into conflict with UAV controllability. Therefore, system reliability sensitivity is redefined and modified to prevent uncontrollable situations during the UAV’s mission. The priority given to each actuator is related to its importance in system reliability. Moreover, the proposed approach can reconfigure the controller to compensate actuator faults and improve the overall system reliability or delay maintenance tasks.

19

Analiza diagnostyczno-niezawodnościowa szyfratora IP

Olesiński Adam, Dąbrowski Tadeusz

Elektronika : konstrukcje, technologie, zastosowania

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2020

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Vol. 61, nr 7

17--22

PL

W artykule przedstawiono analizę diagnostyczno–niezawodnościową szyfratora IP. W tym celu zdefiniowano strukturę fizyczną i funkcjonalną urządzenia. Przedstawiono procesy autodiagnostyczne zachodzące w trakcie jego pracy. Zdefiniowaną strukturę zdekomponowano na moduły a następnie na zbiory elementów elektronicznych, dla których obliczono lub odczytano z dokumentacji wskaźniki niezawodnościowe. Przeprowadzono analizę niezawodnościową dla wyróżnionych modułów, a następnie dla całego urządzenia. Przeprowadzono to z uwzględnieniem różnych struktur niezawodnościowych i temperatur pracy. Znaleziono moduł o najniższej niezawodności i zaproponowano zastosowanie rezerwy nieobciążonej jako sposobu na zwiększenie niezawodności użytkowej urządzenia.

EN

The article presents diagnostic and reliability analysis of the IP encryption device. For purposes of analysis, the physical and functional structure of the device was defined. Autodiagnostic processes occurring during his work were presented. The defined structure was decomposed into modules and then into sets of electronic components for which reliability indexes were calculated or read from the datasheet. The issues of device reliability in relation to the reliability of electronic components were discussed. A reliability analysis was carried out for all modules, and then for the entire device, taking into account various reliability structures and operating temperatures. The module with the lowest reliability was found and it was proposed to use the unloaded reserve as a method to increase device reliability.

20

Reliability analysis of a multi-eso based control strategy for level adjustment control system of quadruped robot under disturbances and failures

Cui Jingjing, Ren Yi, Xu Binghui, Yang Dezhen, Zeng Shengkui

Eksploatacja i Niezawodność

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2020

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Vol. 22, no. 1

42--51

EN

The complexity of control algorithms and their vulnerability to disturbances and failures are the main problems that restrict the operations of multi-legged mobile robots in more complex environments. In this paper, a multiple extended state observer (ESO) based control strategy is proposed to achieve stable tilt angle control for quadruped robots under the influence of disturbances and actuator failures. By treating the multiple legs as parallel control objects, more ESOs were added to improve the disturbance rejection ability of the linear active disturbance rejection control (LADRC). Correlation of interactive information about the legs is realized by the synthesis of multiple ESO information. Based on LADRC, this method has the advantages of easy parameter tuning, good robustness, and strong ability to cope with interference and fault conditions. A control system reliability evaluation method was proposed. The reliability and control performance of the multi-ESO based control system under leg stuck failure conditions were systematically analyzed. Simulation and experimental results for the level adjustment control system of a quadruped robot are provided to verify the disturbance rejection ability, feasibility and practicability of the proposed multi-ESO based control method.

PL

Złożoność algorytmów sterowania oraz ich brak odporności na zakłócenia i uszkodzenia to główne czynniki ograniczające pracę wielonożnych robotów mobilnych w bardziej złożonych środowiskach. W przedstawionym artykule zaproponowano strategię sterowania wykorzystującą kilka obserwatorów stanu rozszerzonego (ESO), która pozwala na uzyskanie stabilnego kąta pochylenia robota czworonożnego w warunkach zakłóceń i uszkodzeń siłowników. Traktując każdą z nóg jako równorzędny obiekt sterowania, dodano dodatkowe ESO, co pozwoliło na poprawienie zdolności algorytmu liniowego aktywnego tłumienia zakłóceń (LADRC) do kompensacji (tłumienia) tych ostatnich. Interaktywne informacje dotyczące poszczególnych nóg korelowano poprzez syntezę danych z ESO. Zaletami omawianej metody opartej na LADRC są: łatwość dostrajania parametrów, wysoka niezawodność oraz bardzo dobra zdolność do radzenia sobie z zakłóceniami i uszkodzeniami. Zaproponowano także metodę oceny niezawodności systemu sterowania. Analizowano niezawodność i wydajność systemu opartego na kilku ESO w warunkach awarii wywołanej zablokowaniem nóg robota. Przedstawiono wyniki badań symulacyjnych i eksperymentalnych systemu sterowania regulacją poziomu robota czworonożnego, które pozwalają zweryfikować zdolność proponowanej metody do tłumienia zakłóceń, a także możliwość jej praktycznego zastosowania.